Carlos rode an average of 9 miles every hour on his bicycle. It is because 3*9=27 and the distance is rate multiplied by time. use the formula and check it!
Hope I helped.
Good Luck!
The formula you have given here is for the volume of a cylinder. It should read

.
First, to find r, the radius, divide the diameter by two (since the radius is the distance from the circumference to the centre and the diameter is the distance from any point on the circumference to the opposite point (through the centre))
r = 8/2 = 4
Now we can calculate this.

If your answer needs to be in litres, one cubic centimetre = one millilitre.
603 cm3 = 603mL = 0.603 L
The volume of the triangluar block is 4 cubic inches. What is the approximate length of y? -- 2.8 inches